JSON to XML Converter

JSON to XML and back: a practical converter for two data worlds

Most developers work with both XML and JSON whether they want to or not. Modern web APIs speak JSON almost exclusively, but the moment you touch a bank, an insurer, a government endpoint, an enterprise ERP, or an old SOAP service, XML shows up again. The JSON to XML converter on this page turns JSON into XML and XML back into JSON directly in your browser, so you can move between these two formats without copying sensitive payloads into a remote service.

What XML and JSON actually are

XML (Extensible Markup Language) is a markup format built around nested tags, attributes, and namespaces. It was designed for documents and structured data interchange, and it carries a lot of machinery: schemas (XSD), namespaces, processing instructions, comments, CDATA sections, and a formal declaration at the top. That richness is why XML still dominates in legacy and enterprise systems. You find it in SOAP web services, RSS and Atom feeds, configuration files (Spring, Maven, .NET app configs), office document formats, and financial messaging standards like SWIFT and ISO 20022, where banks and insurers continue to exchange XML every day.

JSON (JavaScript Object Notation) is far simpler: objects with key/value pairs, arrays, strings, numbers, booleans, and null. It maps almost one-to-one onto the data structures of nearly every programming language, which is exactly why it took over modern web APIs, REST endpoints, mobile apps, and config files like package.json. JSON is typically 30 to 50 percent smaller than the equivalent XML and parses noticeably faster, partly because it drops the closing tags and attribute machinery that make XML verbose.

The key differences that matter for conversion

The two formats overlap enough to map onto each other, but not cleanly. A few structural differences cause almost all of the friction:

• Attributes versus child nodes. XML distinguishes between <user id="1"> (an attribute) and <user><id>1</id></user> (a child element). JSON has no such concept, so converters invent one. By convention attributes are folded into a key such as @attributes or prefixed with @, while element text lands in a key like #text.
• Arrays. JSON has native arrays. XML does not. A list in XML is just the same tag repeated, like three <item> elements in a row. Converters have to infer when repeated siblings should collapse into a JSON array, and when a single element should stay a plain object.
• Namespaces. XML uses namespaces (the xmlns:soap prefixes) to avoid name collisions across schemas. JSON has nothing equivalent, so prefixes either survive as literal characters in keys or get stripped.
• Verbosity and metadata. XML can attach metadata to a node through attributes; JSON expresses everything as keys and values. That makes JSON more compact and easier to read, while XML retains validation power through XSD schemas.

Conversion gotchas to watch for

Round-tripping JSON to XML to JSON and expecting an identical result is the classic mistake. The conversion is lossy in both directions unless you control the rules. Keep these in mind:

• Attributes get mangled. When you convert JSON to XML, the tool needs a rule for which keys become attributes versus elements. When you go the other way, attributes have to land somewhere, and that "somewhere" (@ prefix, @attributes block) differs between libraries. If a downstream parser expects a different convention, the data looks wrong even though nothing was lost.
• Single element versus array. An XML feed with one <item> produces a JSON object; the same feed with two items produces a JSON array. Code that assumes an array breaks on the single-item case. This is a common source of RSS and SOAP parsing bugs.
• Namespaces leak or vanish. Depending on the tool, soap:Body may become a key literally named soap:Body, or the prefix may be dropped entirely, changing the meaning of the document.
• Mixed content and types. XML treats everything as text, so a value like true or 42 may stay a string after conversion to JSON, while the reverse direction has no native place for comments or CDATA.

Why local-only conversion matters

JSON and XML payloads are often the most sensitive thing a developer handles: API responses with tokens, SOAP messages with account numbers, config files with credentials. A converter that runs in your browser never uploads any of that. The parsing and serialization happen on your machine, nothing is sent to a server, and you can use the tool offline once the page has loaded. For debugging production data or anything under a compliance regime, that is the difference between a safe quick check and an accidental data leak.

If you need to clean up the result afterward, pair this with our other data converters, or tidy your output with the JSON formatter before handing it to the next tool in your pipeline.

Frequently asked questions